Ṭāhir ibn al-Ḥusayn

…as by an Iranian general, Ṭāhir. Ṭāhir’s victory over al-Amīn’s army on the outskirts of the present Tehrān allowed al-Maʾmūn’s troops to occupy western Iran. Al-Amīn appealed in vain to new troops recruited in part from among the Arabs of Syria. He was finally besieged in Baghdad in April 812.…

…Iranian Islamic dynasty—was founded by Ṭāhir ibn al-Ḥusayn, a successful military general awarded the eastern lands by the caliph. Ṭāhir’s successors pushed their dominion as far as the Indian frontier.

…ibn Layth’s movement differed from Ṭāhir ibn al-Ḥusayn’s establishment of a dynasty of Iranian governors over Khorasan in 821. The latter’s rise marks the caliph’s recognition, after the difficulties encountered in Iran by Hārūn al-Rashīd (reigned 786–809), that the best way for the imam and amīr al-muʾminīn at Baghdad to…